Aromatizable vs non-aromatizable androgens in cervical ripening

Abstract

SAROSH RANA (F), HUILING JI, VIT LONG, EDWARD CHIEN, Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island, Brown University, Obstetrics and Gynecology, Providence, Rhode Island OBJECTIVE: The regulation of cervical remodeling during pregnancy is poorly understood but is thought to be regulated by steroid hormones. A number of model systems with androgen metabolism abnormalities have disturbances in cervical ripening. These models would suggest that nonaromatizable androgens directly control cervical ripening. 5a-reductase type II converts testosterone to DHT (Dihydrotestosterone), a non-aromatizable androgen. We hypothesize that cervical remodeling is mediated through androgens leading to decreased cervical tensile strength. STUDY DESIGN: Cervical creep (an assessment of tensile strength) was assessed in timed pregnant Sprague-Dawley rats at mid gestation. Treatment groups included three androgenic compounds: Androstenedione (20 mg), Testosterone (2 mg), and DHT (2 mg). Cervical creep was determined using the technique of Hollingsworth. Androgens were administered intravaginally on day 15. Tissue was harvested 16 hrs later. Groups were compared to control using t-test. RESULTS: A significant increase in cervical creep rates were seen after DHT (p = 0.01). No statistically significant difference was detected in rats treated with androstenedione or testosterone when compared to rats in the control group. The effect of testosterone had greater variability then androstenedione or DHT CONCLUSION: The non-aromatizable androgen, DHT, is an effective cervical ripening agent. The conversion of aromatizable androgens to DHT is necessary for androgen induced cervical ripening.